1. Field
One or more embodiments relate to a battery module including a cap assembly structure having high process stability.
2. Description of the Related Art
In general, a secondary battery is a rechargeable and dischargeable battery, which differs from an un-rechargeable primary battery. The secondary battery may be used as an energy source of, e.g., a mobile device, an electric car, a hybrid car, an electric bicycle, an uninterruptible power supply, or the like. The secondary battery may be used as a single battery or a battery module, in which a plurality of batteries are electrically connected to one another by using a bus bar, according to a type of an external device to which the secondary battery is applied.
A small mobile device, e.g., a cellular phone, operates only for a predetermined time based on power and capacity of a single battery. However, if extended periods of driving and a high performance driving are to be performed by an electric car, a hybrid car, or the like, a battery module may be required to provide sufficient power and capacity.
An output voltage or an output current of the battery module is increased according to the number of batteries installed in the battery module. Therefore, the battery module may include a plurality of batteries connected to one another in series or in parallel to obtain the desired output voltage or current of the battery module.